split-cl: Walk the tree instead of using owners db.
split-cl: Walk the tree instead of using owners db.

Change-Id: I9dc9cda5a30833938fe13476deb76f4ed5770eab
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/2666668
Auto-Submit: Edward Lesmes <d05609f027dc667cc37492b1dc1bdea5d60fa82a@chromium.org>
Commit-Queue: Gavin Mak <bdcbd10822f2f5deecea3bf14d73e9025b1b8375@google.com>
Reviewed-by: Gavin Mak <bdcbd10822f2f5deecea3bf14d73e9025b1b8375@google.com>

CoherentLabs/depot_tools,CoherentLabs/depot_tools